AVO class II advanced prospectively workflow for deep miocene in west delta deep marine, offshore Nile Delta, Egypt

Abstract

The West Delta Deep Marine (WDDM) region offshore the Nile Delta in Egypt, which contains significant Pliocene fields, is currently experiencing a decline in production, leading to the exploration of deeper Miocene targets. To tackle this challenge, a proposed an enhanced workflow that utilized sophisticated AVO analysis to detect subtle gas reservoirs within the Miocene strata, corroborated by Direct Hydrocarbon Indicators (DHIs). Prior wells aimed at Messinian and earlier strata frequently encountered water-bearing sands, displaying AVO Class I responses with hard kicks, thereby complicating reservoir differentiation. Our methodology initiates with extensive rock physics modeling to evaluate the potential for AVO Class II responses in Miocene sediments. Fluid substitution techniques and stochastic Monte Carlo simulations were utilized to model gas-bearing responses, with minor amplitude variations in far-offset stacks confirming feasible AVO Class II gas sand scenarios. The seismic analysis of the WDDM region identifies reservoir attributes within an aggradational channel system, shaped by structural elements including the Rosetta fault and offshore anticlines of the Nile Delta. Through the integration of sophisticated DHI support and geological derisking methodologies, multiple promising AVO Class II prospects displaying clear soft kick signatures were identified. These findings improve the success rate for new Miocene exploration targets by accurately differentiating gas sands from water sands, even in instances of weak seismic responses, and offer a framework applicable to analogous deepwater basins with clastic reservoirs and diverse AVO characteristics.